1. Field of the Invention
The present invention relates to a device for supporting a partial denture on a front tooth or a molar tooth.
2. Description of the Prior Art
A device for supporting a partial denture on a front tooth or a molar tooth as shown in FIGS. 10 and 11 is disclosed in, for example, Japanese Utility Model Application Laid-Open No. 57-53260 (1982).
Referring to FIGS. 10 and 11, A designating a denture, B designating a supporting tooth crown, C designating a supporting tooth, D designating a dented portion formed in a neck portion side of said denture A on a side opposite to said supporting tooth crown B, E designating a tooth flesh, and 21 designating a joint member formed of an elastically transformable metallic wire in the form of a loop, there is a base portion side of said joint member 21 arranged in the dented portion D buried in denture A. 22 designates a break formed in said joint member 21, 23 designates a fixture member fixedly mounted on the supporting tooth crown B at an end portion thereof and provided with a rod-like supporting member 24 having a size insertable into the joint member 21 at an end portion thereof. The rod-like supporting member 24 has a slightly larger diameter at an end thereof.
The fixation of the denture by means of this supporting device is carried out in the following manner. The denture A is placed at an appointed position. Then, the joint member 21 is put on the supporting member 24, so that upon pushing the denture A slightly strongly in the direction of tooth flesh E, the pointed end larger diameter portion of the supporting member 24 elastically transforms the joint member 21 by the break 22, thereby inserting the supporting member 24 into the joint member 21. Upon passing the pointed end larger diameter portion of the supporting member 24 through the joint member 21, the joint member 21 is returned to the original state, so that the joint member 21 is engaged with the larger diameter portion of the supporting member 24, whereby the denture A is fixedly mounted on the supporting tooth crown B so as not to be needlessly separated.
When it is necessary to separate the denture A, contrary to the above described case, denture A is slightly strongly moved in the direction of separating the denture A from tooth flesh E to elastically transform the joint member 21, thereby separating the joint member 21 from the supporting member 24.
According to the above described conventional device for supporting a partial denture, it is necessary to give a slightly large force to the denture A in order to slightly elastically transform the joint member 21 in both the event that the denture A is installed and in the event that the denture A is detached. Thus, the problem arises that the denture A is difficult to install and detach.
Besides, as the force for elastically transforming the joint member 21 acts also upon the supporting tooth crown B through the supporting tooth C, a problem arises that the supporting tooth C is subjected to an unreasonable load. Furthermore, because the joint member 21 is subjected to repeated elastical transformations a problem arises that a spring stress of the joint member 21 is apt to be weakened and the useful life of the joint member 21 is relatively short.